Aircraft, particularly commercial aircraft, may include cargo compartments that are partitioned off from passenger compartments within the aircraft. As a safety measure, aircraft of this fashion may include fire suppression systems that are specifically associated with the cargo compartment(s). Such fire suppression systems may operate by introducing a fire suppressant into the compartment, once a combustion event or combustion products associated with a combustion event (e.g., a fire) are detected. In some examples of conventional fire suppression systems, the system may respond to a detected fire in two phases, a knockdown phase followed by a suppression phase. During the knockdown phase, the cargo compartment is flooded with fire suppressant at a high flow rate, whereas during the suppression phase, a lower flow rate of the fire suppressant is provided over an extended period of time.
As the fire suppressants used in such systems may be gaseous or liquid particulates, during detection and/or monitoring phases of the fire suppression systems, the fire suppressants may commingle with combustion products, created by a combustion event. In conventional systems, sensors utilized to detect combustion events via detection of combustion products may provide false alarm signals, due to the existence of fire suppressants commingled with combustion products and/or the general atmospheric air of the cargo compartment. Therefore, false and/or nuisance alarms may cause a flight crew to take unnecessary measures when, in fact, any fire has already been adequately suppressed. Further, false alarms or false monitoring may indicate, to a controller, that excessive flow of fire suppressant is needed in an event wherein a combustion event has or is occurring and said event is, at least in part, suppressed. Therefore, fire suppressant systems, which can accurately delineate between atmospheric substances and combustion products within the atmospheric air of the compartment, are desired. Additionally, fire suppressant systems that include smoke removal for further elimination of false alarms and decreased likelihood of smoke penetration, into the occupied areas of the airplane, are also desired.